Karl Gottfried Hagen (1749-1829)

[This is a draft of an article in The Dictionary of Eighteenth Century German Philosophers, 3 vols., edited by Manfred Kuehn and Heiner Klemme (London/New York: Continuum, 2010).]

Karl Gottfried Hagen was born (24 December 1749) and died (2 March 1829) in Königsberg, where he lectured at the university on experimental chemistry, botany, and pharmacy, and was a regular dinner guest of Immanuel Kant’s during the 1790s. He was an early founder of pharmacology as a university-taught discipline.

Hagen’s father, Heinrich (1709-1772), settled in Königsberg as an apothecary (1728) and eventually married the daughter of the court apothecary (1738), whose practice he later assumed (1746). Karl Gottfried thus grew up in an economically and intellectually successful household. He studied at the Altstadt Gymnasium in Königsberg while apprenticing in the family pharmacy (from age 14), then matriculated at the university in Königsberg (23 January 1769) to study medicine. After his father’s death in 1772 he had to abandon university studies to assume the family business, traveling to Berlin in 1773 for the pharmacy exam required of anyone in Prussia wishing to direct a pharmacy. Although he continued to head the pharmacy until 1816, he resumed his academic pursuits, sat for his examen rigorosum with the medical faculty at Königsberg (20 April 1775), graduated as a doctor of medicine (28 September 1775), and habilitated with a dissertation on tin, after which he offered lectures on botany and experimental chemistry, and later also zoology, physics and mineralogy. In 1779 he became an associate professor, in 1783 an adjunct professor of medicine, and in 1788 a full professor of medicine. In 1789 he became the assessor, and in 1800 the medical advisor, of the provincial health department. With the restructuring of the philosophy faculty in 1807, he was appointed the full professor of chemistry, physics, and natural history in that faculty and was awarded a Ph.D.

In 1784 he married Johanna Maria Rabe (1764-1829), and five of their nine children lived to adulthood: Karl Heinrich (1785-1856; since 1811 the professor of political science at Königsberg, and a former student of Kant and Kraus), Johann Friedrich (1788-1865; assumed the family business in 1816), (Ernst) August (1797-1880; art historian and co-founder of the Neuen Preußischen Provinzial-Blättern), Johanna (married the astronomer F. W. Bessel), and Louise Florentine (married F. E. Neumann, who assumed her father’s vacated professorship of physics and mineralogy). Most prominent were the sons Karl and August, who were given the nick-names — apparently due to a joke made by Friedrich Wilhelm III — Kumsthagen for Karl and Kunsthagen for August. The latter name is obvious, given August’s work in the arts (Kunst); the former is more obscure: ‘Kumst’ is an East Prussian word for Kohl or cabbage, which is a colloquial term for money as well.

Hagen’s pioneering courses on experimental chemistry were quickly imitated in other German universities and his textbooks for these courses were widely used, with multiple editions issued in his lifetime. His Textbook on the Apothecary Art (1778) helped transform what had been a craft into a true science taught in the university. Immanuel Kant, to whose circle of dinner guests Hagen belonged, declared his Outline of Experimental Chemistry (1786) to be “a logical masterpiece,” and Hagen served as an important source of current scientific information for Kant in the 1790s. C. F. Reusch [bio] wrote that Hagen was “highly respected by Kant because of his splendid character and his great knowledge of physics, chemistry, pharmacy, and botany.” In his chemistry lectures, Hagen had at first supported Stahl’s phlogiston theory, but by 1792 recognized the merits of Lavoisier’s work on oxygen, and Kant followed suit (in his preface to the Metaphysics of Morals (AA 6: 207), Kant wrote that “there is only one chemistry (Lavoisier’s)”). Hagen also closely studied the current work on electricity being published by Volta and Galvani. In 1817 he founded the Beiträge zur Kunde Preußens, in which he published numerous essays on local history as well as popularizations of science.